Chapter 11 — Further Reading

Tier 1 — Verified canonical sources

ICD-10-CM Official Guidelines, Section I.C — the chapter-specific guidelines covered here:

• I.C.9 — circulatory system. The hypertension guidance is here, and it is the most important reading in this chapter. Read it in full; it is a few pages and it contains the asymmetry, the myocardial infarction time rule, and the cerebrovascular sequelae guidance.
• I.C.10 — respiratory system, including the respiratory failure sequencing rules.
• I.C.11 — digestive system.
• I.C.13 — musculoskeletal system and connective tissue.
• I.C.12 — skin and subcutaneous tissue, which carries the pressure ulcer guidance.
• I.C.14 — genitourinary system, including chronic kidney disease staging and transplant status.
• I.C.15 — pregnancy, childbirth, and the puerperium. Read this one completely if you will code obstetrics at all — the priority rule, the trimester rules, the seventh character, and the outcome of delivery code are all here, and none of them resembles anything else in the classification.

Section I.A.15 — the "with" convention. Read it alongside I.C.9, because the interaction between them is Case Study 1's subject and is the source of most hypertension coding disagreement.

AHA Coding Clinic. Subscription. Hypertension, heart failure specificity, respiratory failure sequencing, and obstetric coding are all heavily represented, and a great many of the judgment calls this chapter raises have been addressed specifically.

ICD-10-CM annual addenda. The hypertension guidance, the heart failure categories, and the cerebrovascular sequelae categories have all been revised. The addenda are where you see what changed.

ICD-10 Coordination and Maintenance Committee materials — where the hypertension clarifications in Case Study 1 were proposed and discussed publicly.

Tier 2 — Attributed, specifics unverified

AAPC and AHIMA educational material on hypertension coding. This is the single most-written-about convention in diagnosis coding and there is a great deal of explanatory material. Check the date on anything you read — Case Study 1's whole point is that the guidance has been clarified more than once, and older material describes superseded versions.

Cardiology and nephrology specialty society coding guidance. Both areas have societies that publish practical material on the specificity their members' documentation needs to support, and it is frequently better than general coding material because it is written by people who see the same twenty conditions daily.

Clinical documentation integrity literature on heart failure specificity. Case Study 2's cause 3 — physician documentation habit — is a standing CDI focus, and the practitioner literature on how to raise it well is unusually good.

American College of Obstetricians and Gynecologists coding resources, and obstetric coding material generally. Chapter 15 is different enough from the rest of the classification that specialty-specific material earns its place.

Risk-adjustment literature on condition specificity, particularly for heart failure and chronic kidney disease — the two conditions where specificity moves a risk score most and where Case Study 2's mechanism operates.

Tier 3 — Illustrative and constructed

Every clinical scenario in this chapter — the five worked charts in §11.10, all exercise vignettes, and the diagrams in §11.1, §11.4, and §11.8. Constructed. The conventions are real; the clinical situations are invented.

Case Study 2 in its entirety — the fourteen-physician cardiology practice, its unspecified heart failure rate, and the three causes with their proportions. Constructed; the pattern and the mechanism are documented.

Account 10-4471's circulatory analysis.

Two things worth doing

Read Section I.C.9 in full, today. It is the highest-value few pages in Part II for anyone coding adult primary care, cardiology, or nephrology, and it contains the one convention this book calls the most tested in circulatory coding.

Then measure your own unspecified rate for one condition. Case Study 2's method: pull twenty charts coded to an unspecified option and determine, for each, whether the record supported more. The proportions tell you whether you have a coder problem, a policy problem, or a documentation problem — and it is almost never the one you assumed.